So `flutter run --local-engine=...` will work out of the box.

Fixes flutter/flutter#9154.

* add paths_win.cc to FML

* update licenses

* Partially port FML to Windows.

* Adds a message loop impl for Windows
* Ports `thread.cc` to Windows

All FML unittests are now passing on Windows.

FML as a whole does not compile on windows yet because `mapping.cc` imports `sys/mman.h`, which is not available on Windows and the replacement API for memory-mapped files is very different on Windows, see https://msdn.microsoft.com/en-us/library/windows/desktop/aa366556%28v=vs.85%29.aspx.

* update licenses

* review comments

Ensure selection base is updated when deleting surrogates

This fixes a bug in which the selection base was not updated when
deleting at index of the trailing char of a Unicode surrogate,
introduced in 38664ac3.

Minor refactor to consolidate logic around NSRange.

* Handle Unicode surrogates in FlutterTextInputView

Fixes a bug introduced in 38664ac3.

* Maintain FlutterTextInputView text in NSMutableString

We were converting from/to NSString at the interface of
FlutterTextInputView; instead use NSMutableString to maintain the
internal buffer.

Eliminates nsstring_utils.{h,mm} which no longer has any users.

* Roll FTL to 77f430179ddc1ad82e9ad3c056b708f583804151

This makes FTL compilable on Windows.

* fix license

Fix a race condition in MessageLoopImpl due to difference in calculation of the next wake and the timer rearm. (#3548)

Fixes https://github.com/flutter/flutter/issues/9129

This reverts commit fa360b55.

* Name the platform thread in the timeline. This does not affect (nor is it affected by) the pthread name set by the embedder.
* Make it easier in the timeline to see not only when the frame was request, but also when that frame request was fulfilled.
* Trace message loop wakes.

This reverts commit afb206d3.

The Java message object may be held by user-provided message handlers beyond
the lifetime of the raw blink::PlatformMessage and its data buffer

This type appears to be missing in older Mac SDKs.

* Roll Skia revision to 342977ced701d06df2b3d2eedd8b64aeae1eb5c5

* Updated license files

android_tools contains a toolchain that is specific to each host platform

Fixes https://github.com/flutter/flutter/issues/8969

FragmentActivity is required for plugins that use auto managed Google APIs, such as Google Sign-In. Requires flutter/flutter#9036 to land so that gradle builds include FragmentActivity.